Dynamo-electric machine.



No. 822,697. PATENTED JUNE 5, 1906.

W. STANLEY.

DYNAMO ELECTRIC MACHINE.

APPLICATION FILED MAY 25. 1905.

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PATENTED JUNE5,190 6. w. STANLEY. DYNAMO ELECTRIC MACHINE. AP'PLIUATIONFILED MAY 25. 1905.

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v 'vention in its preferred form, but has dis.-

. motive forces differing in phase in the rotor Figure 1 represents oneembodiment of my if M310, (Lil wlton'z, it may concern: r Be it:knownthat I, WILL rAM'SrANLn a citizen of the United States, residing at 7Great Barrington, county of Berkshire, State 5 of Massachusetts, haveinvented certain new ,g and. useful Improvements in DynamoJEle'c- .tricMachines, of which the following is a full, clear, 'and exactdescription.

My invention relates to alternating-cur IO rentjdynamo-electric machineshaving alter- ;:i;nat e-current excitation, and particularly to machinesof the polar type.

has for its object to produce an alternating current dynamo-electricmachine of I 5 the polar type which is self-excited byalteritnatingcurrents.

have discovered that if currents are induced in'the rotor-windings of adynamoelectric machine and conducted to energiz- 2ov ing' windings whichproduce' a field which do'e's'n'ot coincide with the field of the rotorthe r'nachine will be self-excited by alternatin'g' currents. I "Inaprior application filed by me on the 2.5 Zdday of February, 1905,SerialNo. 243,842, 23' I have described such a machine and broadlyclaimed the inventions embodied therein. Thehmachine of this applicationis one whi h embodies the same fundamental insymmetrically-formedwindings as distinguished from symmetrically-formed windingsdissynnnetriially located. In this type of machine the polar typeis thepreferred 35 form,fand the windings are symmetrically located around thestator structure, but are grouped dissymmetrically with reference tocurrents flowing from the two phases of the rotor, the result being theproduction of a 4o dissymmetrical field or one whose: center doesinotcorrespond with the center of the rotorfield. The resultant flux of therotor and stator, therefore, as it revolves around the rotor and statorwindings induces electroand stator circuits.

The machine has the advantage of having a more definite neutral zoneupon the commutator and has in addition the advantages 50 ofconstruction accompanying machines of the polar type. p

The following is a description of my invention, reference being had tothe accompany ing drawings, in whichinvention. Figs. 2 and 3 showdiagrams for Specification of Letters Patent.

Application filed May 25,1905. serislno. 262,182.

i DYNAMO=ELECTFHQ MACHINE r I Patented June 5, 1.9063

explaining a modification .of the same, i

4. shows't he modification referred to. Fig; 5 shows the modificationhaving compoundingor compensating coils added. Fig. 6 shows themodification with compounding or compensating coils of different forms.Fig. 7 is a diagram of" generated electromotive forces. Fig. 8 is'avector diagram of electromotive forces and fluxes. 5

Referring more particularly to the drawings, A is a rotor havingpreferably awind ing of the ordinary distributed type, and a commutatorB, having its segments .connected to the windings of the rotor A inthe 70 ordinary way. '0 D and E F are brushes bearing on said commutator. G Gand H H are main energizing or field coils connected to said brushes'C,D,E, and F. 1

I I J J are deflectingwindings in series'75 with and of fewer turns thanthe windings G G H H and placed upon the succeeding poles and connectedto. the succeeding brushes, respectively. p y j The coils I I and J Jhave induced in them 30 effective electromotive forces driving themagnetizing-currents through the main field: coils G G and H H. Thus wehave coils I I on diametrically opposite poles receiving fluxes fromcoils H H and having electro 5 motive forces induced in them and inseries with the coils G G on poles which in this embodiment are at rightangles to the coils I I. The electromotive forces induced in the coils II by the currents in the coils H-H drive the -9 current through thecircuits G I and produce a nearly vertical field. The coils J J haveinduced in them by the fluxes from the coils G G electromotive forceswhich drive the current through the coils H H and produce a horizontalfield. a

The currents passing through the coils G G and H H are of differentphase resultin in a magnetic field rotating in a clockwise iriaction,the same as the rotor. The electromo I00 tive forces generated in therotor-windings depend u on the difference between t-he mag-' netic anmechanical rotations. The commutator B alters the frequency of the currents delivered at the brushes by co1n1nutat- 5 ing out the frequencydue tomochanical rotation of the rotor,-so that it corresponds to thespeed of magnetic rotation without regard to the speed of mechanicalrotation. The dynamo 1s therefcre self-exciting and has a frequencydepending upon the magnetic rotation.

v The production of the rotating field may be explained as follows: Thedifference of potential between two adjacent brush.csfor instance, F andl)givcs a current which energizes the coils I I and J, and this currentproduces a flux whose polar line is practiccally horizontal. 'lhereforewhile the llux which has generated the difference of potential betweenthe brushes F and l) is a vertical flux the flux produced by thisclectromotive force (between F and Dj is horizontal-that is to say,ninety degrees away from the other flux. The flux due to the'electromotive force between the brushes F and D does not, as in thenormal self-exciting machine, reinforce the flux which has produced theelectromotive force between F and D, but is shifted ahead ninety degreesin position and produces an electromotive force between the brushes Dand E. This electromotive force between the brushes D and E produces aflux which gives an elcctroniotive force between the brushes E and C,and so on, the result being that the flux of the machine has not a fixedpolar line, but is a revolving field, and in consequence theelectromotive forces generated in the machine are of polyphasecharacter.

The diagram of Fig. 7 gives the relative phase relation ofthe/electromotive forces represented by the lines F D, C F, E C, and DE, corresponding to the electromotive forces between the brushes F andI), the brushes C and F, the brushes E and F, and the brushes D and E.It also gives the phase relation between the terminal electro motiveforces, the same being in quadrature. These terminal electromotivcforces are represented by C D-and E F, which. correspond, respectively,to the electromotive forces between the brushes C and D and the brushesE and F.

Fig. 8 represents a simple vector diagram showing the action of thefields. F D and l) E are electromotive forces existing between theadjacent brushes F and l) and the adjacent brushes D and E. Theelcctromotivc force F D sends through the coils H J, to which thebrushes F and D are connected, a current which lags almost ninetydegrees behind the electromotive force F and l). The. current lowingthrough the coil ll is reprc sented in the diagram by the vector II, andthe current flowing through the coil J is represented in the diagram bythe vector J. J is opposite in direction to II because the coil J isreversed inv its connection with the coil ll Analogously theelectromotivc force I) and 1) sends through the coil I a current(represented in the diagram by l) lagging almost ninety degrees behindthe ,electromotivc force l) E and through the coil G a current(represented by G) opposite to 1:. The magnetization of the poleopposite the brushes l) E, Fig. l, is tlren due tothe resultant of ll1.. This resultant flux F is in phase with. the electrolnotive force 1)E. and the electron'iotivc force .l) E is actually produced by the rotation of the armature in this resultant; flux F. The same phenomenonoccurs in the other poles of the machine. in other-words, each set ofadjacent brushes cnergizr; a pole ninety degrees away in position. Owingto the resistance of the windings the current sent by the clectromotiveforce D F, for instance, through the coil I'l, lags behind D F less thanninety degrees in time. Therefore another coil I is wound on the samepole and is energized by a current flowing fro1n the brushes D and E,the function of this coil I being to bring the flux exactly inquadrature with the electromotive force 1) F. Then the electronmtive.force D R will lag exactly ninety degrees behind the electromotive forceD F, and the phenomenon. being cyclic around the machine theclectromotive force D C, Fig. 1, will lag exactly ninety degrees behindthe electromotive force E F.

Fig. 4 shows another type of field-coil. connection, of which one phaseis shown in simplified form in Figs. 2 and 3. In Fig. 2 the coils a (L e(I. are connected in series with the coils b b b I). The direction ofthe currents in the two coils (L and l) at top and bottom is opposite,while the direction of the currents in the coils a and b on each of thetwo horizontal poles the same, as shown by the arrows. Since all thecoils u and l) are in series, their l'luxcsare in phase and give thevertical poles a magnctomotivc force equal to a minus 1), (c 5,) as thecurrents in the coils (t and b are opposite, while in the horizontalpoles the magnetoinotivc force is (1. plus 6, (a 1),) as the currentsare in the same direction. equivalent of this arrangement is that shownin Fig. 3: where the coils a and b on each pole are compounded into asingle coil of a minus I) (11 b) or (1 plus I) ((I-hb) turns, the coilsbeing markml, respectively, (e-b) and (n+0).

Fig. 4 shows the connection of two phases arranged on th s plan. Thecoils of the vertical poles of one phase have (w 1)) turns and aremarked (it 1)), and the coils of the horizontal poles of the same phase(c+l)) turns and are marked ((L+ 1)), while the coils of the verticalpoles of the other phases have (u 11') turns and are marked (KL-lb), andthe (.Uflh of the horizontal poles of that phase have ((t- (1) turns andare marked (It The dissymmetrical construction of thesesym1nctrically-arralige l coils results in a lack of coincidence betweenthe stator-field and the rotor-field. Thus when either circuit has amaximum current, the current of the other circuit being zero, the mainenergizing-coils exert a maximum magnetizing effect, while thedeflecting-coils in series therewith also act to magnetizc their poles.On account of the dill'erenec in the number of turns in the. mainenergizing-coils and the deflecting- The ward against the direction ofrotation.

coils in series therewith the polar line is not in the center of iigurebetween any two t(l]ttcent polar projections, but is deflected back- Theeffector this distortion is to produce an electroniotive force tendingto urge a current of phases.

Fig. 5 shows the machine of Fig. 4 with compounding coils added thereto.vIn this figure the coils G G correspond to the coils (cr- 1)). of Fig.4, and the coils'l I correspond ditionto these coils two sets ofcompounding tothe coils (a+ b) of Fig. 4. The coils l i .ll.''

correspond to the coils ((t'b)'-, and the coils J? J5 correspond to thecoils (o+ b). Ina-d coils K and L are placed upon the poles in scrieswith tho work-circuit or one phase, while two setsof compounding coils Mand h are placed upon the poles in. series with. the workcircuit of theother phase. The compound mg i to the coils (a+ b) of Fig. 4.

i coils of one circuit are displaced by ninety degrees from theenergizingcoils of that circuit,

which are wound in the same direction. This is the arrangement when theW0l'l(-('-l1(}llll is de liv.eri-ng unity power current, since themagnetizing forces of the compounding coils are thereby made to be inphase with the magnetizing forces of the energizing-coils of the otherphase,'whose currents lag ninety degrees behind their electroniotiveforces. The displacement of the compounding coils is equal to thecomplement of the angle of lag of the current in the work-circuit. Thisis the general rule and is substantially correct for zero or unitypower-factor work-currents and. also for work-currents of other powerfactors.

In Fig. 6 another arrangement is shown, in which the coils G G"correspond to the coils (ab) of Fig. 4,- and the coils I 1 correspondThe coils J J correspond to the coils (a+?1)' and the coils II ll.correspond to the coils (a, b)? The compounding coils, instead or beingseparate, in Fig. 5, are consolidated and each embraces two polarprojections. Thus the two compounding coils K I; each surround two polarprojections ad iacent to one diameter, While the two compounding coils MN each embrace the polar projections adjacent to a diameter ninetydegrees therefrom. In this case the center of figure of the compoundingcoils coincides with the center of figure of the cncrgizingcoilsbelonging to the same circuit and traversed by currents in the oppositedirection and is displaced byninety degrees l'rom the center of figureof the energizingcoils of the other circuit, which are t avcrsed bycurrents inthe opposite direction. This arrangemen t is the proper onewhen a negative potential gradient is desired, and when thework-circuits are delivering zero-powerfactor currents, the displacementbeing the complement 01'' the angle oilag in the workcircuits. Themagnetizing forces. of the compounding coils are in phase with andopposed to the magnetizing Forces of the energizing-coils, so that asthe "load increases the potential falls, or, in other words, thepotential gradient is negative.

The compounding coils, as shown, are connected in such a way that theentire current of the work-circuit flows tln'ough them, as distinguishedfrom the current from the stator or rotor circuits. lit is not, however,necessary to have the entire current flow through the compounding coils.If the compounding coils are displaced from their corresponding'mainenergizing coils by an angle equal to thc complen'icnt oi the angle oflag of the tcurrent in the work-circuits, they will act to modify theentire magnetizing flux of one phase of the machine. With the coilswound as indicated the magnetomotivc force of the mainenergizing-windings and the compounding coils always assist one anotherinstead of opposing one another. The compounding coils, therefore, tendto increase the magnetizaion of the machine as the work-currentsincrease. If the compounding coils were wound so as to oppose themagnetization of the main energizing-coils, the cllcct of the increaseof current in the work-circuit would obviously be to decrease the ol'the machine.

in the arrangement shown in Figs. 5 and (i the action of the compoundingcoils is to increase the fluxof one phase by unity-powerfactor currentsin the other. Such increase oi" flux tends to .increase the.electromotivc force eliectiw. in driving the magnetizingcurrcnt from thebrush to which the compounding coil is connected. In other words, toincrease the electromotive force magnetizing the machine, andconsequently to increas, its potential. It, however, has but littleinfluence in increasing the flux and lectromotive force of the machinewhen a power-fac tor zero or lagging current is flowing through thecompounding coils, for the reason that then the fiux produced is atright angles to the flux of the machine 'and does not directly assistit. i I

The compounding coils may be said to act by producing magnetism in themachine which generates such an electromotivc force to increase themagnetization.

Various windings and connections may be used in carrying out myinvention in connection with the polar type, as will be obvious to thoseskilled in the art. a

While I do not desire to'beunderstood as limiting my broad invention toany one of magnetization Correction in Letters Patent No. 822.697.

the phrticular forms shown and described, what 1 claim is' 1. In adynainc-electric machine, the combination of a rotor and a stator, oneof said members having windings thereon, a commutator connected thereto,brushes bearing on said comnnitator, and the other of said membershaving polar projections, multiphase windings thereon connected to saidbrushes and producing a field t'lissx'lntnetrical relatively to thefield produced by the other of said windings.

2. In a dynamo-electric machine the combination of a rotor, windingsthereon, a commutator connected thereto, brushes bearing thereon, astator having polar projections, multiphase windings on said stator,connected to said brushes and producing a 'lield dis-- symmetricalrelatively to the field produced by the windings on the rotor.

3. In a dynamo-electric machine, the combination of a stator-winding, arotor-winding electrically connected thereto, said stator Winding beingdissymnietrical in form so that the center of ilux produced by eachphase of current does not coincide with the center of figure of thestator-coils producing it.

4. In a dynamo-electric machine, the com bination of a stator-winding, arotor-winding electrically connected thereto, polar projections for saidstator-windings, said rotor- Winding being synnnetrical in lorm and saidstator-Winding being dissymmetrical inform so that the center of fluxproduced by said stator-Winding does not coincide with the center offlux produced by said rotor-windmg.

5. in a dynamo-electric machine, the combination of the stator-windingand rotorwinding, a commutator connected to said rotor-winding, brushesbearing upon said coinmutator and connected to said stator-winding, saidstator-winding being of such dissymn'ietrical form as to have itselcctromotive l'orce displaced in phase't'rom the electrometivc loreeot' the rotor-winding to which it is connct'rtcd.

6. in a d ynamo-electric machine, the combinat ion ol the stator-windingand the rotorwinding, a commutator connected to said r0- tor-wimling,brushes bearing upon said commutator and connected to saidstator-winding, said stator-winding being dissymmetrical in form so thatthe center of its magnetic field does not coincide with the center ofits figure In a dynamo-electric machine, the combination of a rotor,windings thereon, a com mutator connected thereto, brushes bearingthereon, a stator having polar projections, multiphase windings on saidstator connected to said brushes and producing a field dissymmetricalrelativelv to the field produced by the windings on-the rotor, andcompounding coils traversed by work-circuit currents and so disposedrelatively to the energizing-coils as to superimpose a rotating magneticfield varying with the load,

8. in a dynamo-clcctric machine, the combination of rotor, windingsthereon, a commutator connected thereto, brushes hearing thereon, astator having polar projections, multiphase windings on said statorconnected to sal brushes and producing a field dissymmetrical relativelyto the field produced by the windings on the rotor, and compoundingcoils traversed by the Worlccircuit currents and so disposed relativelyto the energizing-coils as to superimpose a rotating magnetic lieldvarying with the load, the compounding coils being in series with saidWorkcircuit and displaced from said energizing-coils by approximatelythe complement oi lag of the currents in said work-circuits.

WILLIAM STANLEY.

Witnesses A. B. BROWNELL, Ii. Vnnnmnn.

It is hereby certified that in Letters Patent No. 822,697, granted June5, 1906,

upon the application of William Stanley, of Great Barrington,Massachusetts, for an improvement in Dynamo-Electric Machines, an errorappears in the printed specification requiring correction, as follows:In line 116, page 2, the word phases should read phase and that the saidLetters Patent should be read with this correction therein v that thesame may conform to the record of the case in the Patent Ofiice.

Signed and sealed this 'lQthday of June, A. 1)., 1906.

[SEAL] r. ALLEN,

Commissioner of Patents.

